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3 years ago

15

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1 answer:

stealth61 [152]3 years ago

3 0

x³ + ax² + 5x + 3. x + 2 = 0

x = -2

(-2)³ + a(-2)² + 5(-2) + 3 = 0

-8 + 4a - 10 + 3 = 0

4a - 15 = 0

4a = 15

a = 15/4

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The fuel tank of a certain airplane can hold up to gallons of fuel. Let be the total weight of the airplane (in pounds). Let be

zloy xaker [14]

A reasonable function is W = 7F + 5000

Where W is the weight of the plane and F is the number of gallons of fuel.

The domain is the set of possible values for F. That is from 0 (empty tank) to 400 (full tank).

So the domain is F = [0,400], or what is equivalente 0 ≤ F ≤ 400.

The range is the set of values of W.

The minimum value of W is when F = 0 => W = 7(0) + 5000 = 5,000.

The maximum value of W is when F = 400 => W = 7(400) + 5000 = 7,800

So the range is W = [5,000 ; 7,800], pr 5000 ≤ W ≤ 7,800.

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3 years ago

Darius deposits $300 into a new savings account. The account earns at a rate of 2.18% every 6 months. How much money does Darius

MAVERICK [17]

45.87= 2.18 plus 300 is 345.87 hope this is correct if not im soooo sorry

5 0

4 years ago

A major credit card company has determined that customers charge between $100 and $1100 per month. If the monthly amount charged

Alexxx [7]

Answer:

a) $E(X) = \frac{a+b}{2} = \frac{100+1100}{2}=600$

b) First we need to calculate the variance given by this formula:

$Var(X) = \frac{(b-a)^2}{12}= \frac{(1100-100)^2}{12} = 83333.33$

And the deviation would be:

$Sd(X) = \sqrt{83333.33}= 288.675$

c) $P(600 < X< 889) = P(X$

And using the cdf we got:

$P(600 < X< 889)= F(889) -F(600) = \frac{889-100}{1000} -\frac{600-100}{1000}= 0.789- 0.5= 0.289$

d) $P(311 < X< 889)= F(889) -F(311) = \frac{889-100}{1000} -\frac{311-100}{1000}= 0.789- 0.211= 0.578$

Step-by-step explanation:

For this case we define the random variable X who represent the customers charge, and the distribution for X on this case is:

$X \sim Unif (a= 100, b=1100)$

Part a

For this case the average is given by the expected value and we can use the following formula:

$E(X) = \frac{a+b}{2} = \frac{100+1100}{2}=600$

Part b

First we need to calculate the variance given by this formula:

$Var(X) = \frac{(b-a)^2}{12}= \frac{(1100-100)^2}{12} = 83333.33$

And the deviation would be:

$Sd(X) = \sqrt{83333.33}= 288.675$

Part c

For this case we want to find the percent between 600 and 889, so we can use the cumulative distribution function given by:

$F(x) = \frac{X -100}{1100-100}= \frac{x-100}{1000}, 100 \leq X \leq 1100$

And we can find this probability:

$P(600 < X< 889) = P(X$

And using the cdf we got:

$P(600 < X< 889)= F(889) -F(600) = \frac{889-100}{1000} -\frac{600-100}{1000}= 0.789- 0.5= 0.289$

Part d

$P(311 < X< 889) = P(X$

And using the cdf we got:

$P(311 < X< 889)= F(889) -F(311) = \frac{889-100}{1000} -\frac{311-100}{1000}= 0.789- 0.211= 0.578$

6 0

3 years ago

Convert ratio 37 : 500 into percentage

EleoNora [17]

Answer:7.4%

Step-by-step explanation:

6 0

3 years ago

What is the fraction of 3\4 of 28

pentagon [3]

If you are trying to find 3/4 of 28, multiply 3/4 (or 0.75( by 28), which equals 21.

3/4 • 28 = 21

3 0

4 years ago